Document Campaign snapshot integration

README.md

@@ -57,6 +57,12 @@ Umlauf -> workflow execution over recipients, actors, tasks, and deadlines
 CampaignVersion/Report/WorkflowRun -> immutable snapshot of expanded recipients
 ```
 
+Campaign consumes the optional `dist_lists.source` and `dist_lists.expand`
+capabilities. Its Recipient data surface can enter list parameters, preview all
+decisions, freeze a snapshot, and deliberately refresh when the list revision
+drifts. The Campaign copy retains list/revision/entry/provider/channel evidence;
+Campaign enrichment and review never write back to the reusable list.
+
 ## Development Install
 
 ```bash

docs/IMPLEMENTATION_PLAN.md

@@ -91,9 +91,10 @@ definition with execution.
 
 Tasks:
 
-- let Campaign consume snapshots for explicit hybrid-channel routing
+- [x] let Campaign discover, preview, freeze, import, and drift-check immutable snapshots without module imports
+- let Campaign complete explicit hybrid-channel routing and printable output
 - let Reporting consume snapshots for parameterized tables and exports
 - let Workflow consume distribution-list expansion snapshots
 - support ordered participant sequences where workflow owns state
 - add escalation and substitution hooks through workflow, not distribution lists
-- preserve immutable recipient evidence for every execution
+- [x] preserve immutable recipient, exclusion, source, provider, and channel-decision evidence in Campaign versions